v3.5.0.2
Stock incentive plans - General (Details) - 2011 Plan
6 Months Ended
Jun. 30, 2016
shares
Stock incentive plans  
Annual percentage increase alternative, increase in common stock reserved for issuance as a percentage of common stock outstanding 4.50%
Annual fixed increase alternative, increase in shares of common stock reserved for issuance (in shares) 3,000,000
Common stock shares reserved for issuance 12,004,534